Baker‘s Yeast
With some 40 genera and over 500 species, yeast is the best-known and most-investigated microorganism. We can no longer imagine the food, pharmaceutical and cosmetics industries not using fungi. The yeast cell, which measures only 5 to 10 microns, contains a great variety of useful constituents which can be processed further using the separation technology of GEA Westfalia Separator.
The stringent requirements on shelf-life and colour for baker‘s yeast necessitate a multi-stage separation and washing process. To this end, the biomass first has to be separated and concentrated out of the fermentation broth. At the same time, multi-stage washing of the yeast concentrate is also intended to remove the dark colour of the molasses as well as residues of the fermentable substrate between the cells.
Various configurations of separator are conceivable for this task. A distinction is made according to the separator performance required and according to the desired number of washing stages to be installed. In principle, the size of the separators is based on the volumes to be processed; in turn, these depend on the size of the fermenter and the required duration of separation.
The number of separators is based on the flexibility desired and on the washing effect targeted. The following applies: the more washing stages there are, the higher the purity of the baker‘s yeast obtained. Less fresh water also has to be used to achieve the same washing effect.
Integrated process line from GEA Westfalia Separator for obtaining baker‘s yeast
Process line for baker‘s yeast
Installations with three stages or more are the industry standard
Series connection of three or more separators is the current standard in the fermentation industry. These models use the principle of counter-current washing. To do this, the concentrate from the first separator is mixed with the clear phase from the third separator and fed to the second separator for separation. The concentrate from the second separator, on the other hand, has fresh water added to it.
From the first to the last separation stage, the biomass is concentrated and the soluble substances in the intracellular fluid are reduced. Additional washing stages reduce the quantity of wash water required. The baker‘s yeast obtained in this manner is of a very high quality in terms of both cell activity and colour and thus meets the requirements of both small and large bakeries.